A defense that sagged, thanks to the inability of the offense to hold onto the ball.

Those factors added up to a crushing Big Ten Conference loss for Wisconsin as Nebraska twice wiped out deficits of 17 points to stun UW, 30-27, Saturday night at Memorial Stadium.

UW, which wasted a three-touchdown effort by tailback Montee Ball, left four huge points on the field as freshman kicker Jack Russell missed an extra-point attempt early in the second quarter and a 41-yard field-goal attempt in the final minute of the half.

That allowed Nebraska to stay within 20-10 at halftime, and the Cornhuskers, led by quarterback Taylor Martinez and an inspired defense, dominated the second half.

Martinez finished with 288 of Nebraska's 446 total yards. He completed 17 of 29 passes for 181 yards and two touchdowns and rushed 13 times for 107 yards and a touchdown.

Martinez scored on a 38-yard run to cap a four-play, 77-yard drive and added a 10-yard touchdown pass to tight end Kyler Reed to cap a 75-yard drive and help the Cornhuskers pull within 27-24 with 3 minutes 47 seconds left in the third quarter.

Nebraska limited UW to 90 yards on 31 plays in the second half and to 56 rushing yards on 41 attempts overall.

UW's lone second-half score was a 2-yard run by Ball with 10:29 left in the third quarter.

That gave UW a 27-10 lead and capped a 13-yard drive set up by a fumble by Martinez, who was sacked by end David Gilbert.

After Martinez found Reed for the 10-yard score, kicker Brett Maher capped scoring drives with field goals of 38 and 41 yards to help the Cornhuskers take a 30-27 lead with 9:41 remaining in the game.

UW lost quarterback Joel Stave (unspecified injury) on its next possession, which ended in a punt.

Leading, 30-27, the Cornhuskers took over at their 21 with 7:53 left.

They picked up two first downs, the second on an 18-yard strike from Martinez to Kenny Bell to the UW 44 with 4:53 left. UW's defense forced a punt when Martinez threw incomplete on third down, and the Badgers got the ball at the 10 with 2:55 left.

Danny O'Brien, who started UW's first two games before losing his job to Stave, led the offense onto the field.

O'Brien completed passes on the first two plays of the drive. An interference penalty moved the ball to the UW 40.

A low shotgun snap resulted in a 5-yard loss and left UW in a third-and-11 hole.

O'Brien hit Jordan Fredrick for 10 yards to the 49, setting up fourth and 1.

The officials on the field ruled Fredrick had picked up the first down, but the replay booth ruled Fredrick was a yard short.

UW's hopes died when Ball lost a fumble and the Cornhuskers recovered with 1:11 left.

Game over.

The loss left UW (3-2, 0-1) limping into a key two-week stretch against Leaders Division foes.

Nebraska, which suffered an embarrassing 48-17 loss at UW in its first-ever Big Ten game last season, improved to 4-1 and 1-0.

Ball rushed 17 times for 59 yards and two touchdowns in the first half. He was held to 31 yards and a touchdown on 15 carries in the second half.

"That's big-time," Nebraska linebacker Will Compton said of Nebraska's rushing defense. "That was awesome to do."

The fourth-down play was doomed from the start.

Ball took the handoff from O'Brien and started to his right.

Linebacker Alonzo Whaley shot through from Ball's left and made initial contact. Ball didn't appear to have a firm grip on the ball, which fell to the ground.

Safety Harvey Jackson scooped up the loose ball and the comeback, save for two kneel-downs by Martinez, was complete.

"The defensive line got a big push," Compton said, referring to the fourth-down play.

Martinez, who entered the night completing 70.7% of his passes, with nine touchdowns and one interception, made plays all night.

"Martinez to this point has performed as well as anybody in our conference numbers wise," UW coach Bret Bielema said before the game. "I know everybody's got. . . we had a Heisman hopeful to begin with and everything else.

"But Martinez, some of those numbers are pretty hard to beat."

With a crowd of 85,962 in the house, the fifth-largest in program history, UW needed a fast start.

The Badgers got it, thanks to their special teams, defense and offense.

First the kickoff-coverage unit pinned the Cornhuskers at their 11 as they held Ameer Abdullah to an 11-yard return.

The defense, with Gilbert sitting the first two plays for his critical comments about Martinez, recorded a three-and-out.

On UW's second offensive play, Stave executed a play-action fake and hit Jared Abbrederis for 54 yards to the Nebraska 15.

Ball scored on a 2-yard run three plays later, the first rushing touchdown allowed by Nebraska this season.

Nebraska kept making mistakes and UW kept scoring points.

A fumble by Nebraska I-back Rex Burkhead was recovered by linebacker Chris Borland at the Cornhuskers' 23 with 10:49 left in the opening quarter.

UW turned that mistake into another touchdown, with Ball scoring from 1 yard with 7:20 left.